From: Andy Lutomirski <luto@kernel.org>
To: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>, Borislav Petkov <bp@suse.de>,
Andrew Lutomirski <luto@kernel.org>, X86 ML <x86@kernel.org>,
Len Brown <len.brown@intel.com>,
Dave Hansen <dave.hansen@intel.com>,
"Liu, Jing2" <jing2.liu@intel.com>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 14/22] x86/fpu/xstate: Inherit dynamic user state when used in the parent
Date: Thu, 19 Nov 2020 21:08:03 -0800 [thread overview]
Message-ID: <CALCETrWhw_PfdhTY6zzewwwwB35x5LFDouZJ8+C_pcePNc69-w@mail.gmail.com> (raw)
In-Reply-To: <20201119233257.2939-15-chang.seok.bae@intel.com>
On Thu, Nov 19, 2020 at 3:37 PM Chang S. Bae <chang.seok.bae@intel.com> wrote:
>
> When a new task is created, the kernel copies all the states from the
> parent. If the parent already has any dynamic user state in use, the new
> task has to expand the XSAVE buffer to save them. Also, disable the
> associated first-use fault.
This seems like a mistake. If init uses AMX for some misguided
reason, ever task on the whole system will end up with AMX state
allocated.
next prev parent reply other threads:[~2020-11-20 5:08 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-19 23:32 [PATCH v2 00/22] x86: Support Intel Advanced Matrix Extensions Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 01/22] x86/fpu/xstate: Modify area init helper prototypes to access all the possible areas Chang S. Bae
2020-12-07 17:12 ` Borislav Petkov
2020-12-07 23:03 ` Bae, Chang Seok
2020-12-07 23:10 ` Borislav Petkov
2020-11-19 23:32 ` [PATCH v2 02/22] x86/fpu/xstate: Modify xstate copy " Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 03/22] x86/fpu/xstate: Modify address finder " Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 04/22] x86/fpu/xstate: Modify save and restore helper " Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 05/22] x86/fpu/xstate: Introduce a new variable for dynamic user states Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 06/22] x86/fpu/xstate: Outline dynamic xstate area size in the task context Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 07/22] x86/fpu/xstate: Introduce helpers to manage an xstate area dynamically Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 08/22] x86/fpu/xstate: Define the scope of the initial xstate data Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 09/22] x86/fpu/xstate: Introduce wrapper functions for organizing xstate area access Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 10/22] x86/fpu/xstate: Update xstate save function for supporting dynamic user xstate Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 11/22] x86/fpu/xstate: Update xstate area address finder " Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 12/22] x86/fpu/xstate: Update xstate context copy function for supporting dynamic area Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 13/22] x86/fpu/xstate: Expand dynamic user state area on first use Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 14/22] x86/fpu/xstate: Inherit dynamic user state when used in the parent Chang S. Bae
2020-11-20 5:08 ` Andy Lutomirski [this message]
2020-11-24 18:35 ` Len Brown
2020-11-19 23:32 ` [PATCH v2 15/22] x86/fpu/xstate: Support ptracer-induced xstate area expansion Chang S. Bae
2020-11-20 5:07 ` Andy Lutomirski
2020-11-24 18:22 ` Bae, Chang Seok
2020-11-24 18:33 ` Andy Lutomirski
2020-12-02 4:00 ` Bae, Chang Seok
2020-12-03 5:00 ` Andy Lutomirski
2020-12-08 19:12 ` Bae, Chang Seok
2020-11-19 23:32 ` [PATCH v2 16/22] x86/fpu/xstate: Extend the table for mapping xstate components with features Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 17/22] x86/cpufeatures/amx: Enumerate Advanced Matrix Extension (AMX) feature bits Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 18/22] x86/fpu/amx: Define AMX state components and have it used for boot-time checks Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 19/22] x86/fpu/amx: Enable the AMX feature in 64-bit mode Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 20/22] selftest/x86/amx: Include test cases for the AMX state management Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 21/22] x86/fpu/xstate: Support dynamic user state in the signal handling path Chang S. Bae
2020-11-19 23:32 ` [PATCH v2 22/22] x86/fpu/xstate: Introduce boot-parameters for control some state component support Chang S. Bae
2020-11-20 5:02 ` Andy Lutomirski
2020-11-24 18:50 ` Len Brown
2020-11-24 23:41 ` Andy Lutomirski
2020-12-01 18:00 ` Len Brown
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